1. Field of the Invention
The present invention relates generally to decompression devices for internal combustion engines and, more particularly, to an aftermarket cylinder decompression device for motorcycle engines for activation during engine start up and the method for making same.
2. Descridption of the Related Art
Internal combustion engines and other high compression engines require a large cranking torque in order to start the engine. This can be especially difficult during cold starts. The large amount of cranking torque required places a great strain on starter motor and battery life often resulting in premature failure.
Various mechanism have been developed in order to provide compression relief during starting such as relief valves, decompression ports, and decompression slots formed in the walls of the cylinder. These devices vent a portion of the internal cylinder pressure during the compression stroke during startup in internal combustion engines thereby reducing the amount of torque needed to turn the crankshaft during start up.
In the related art, there exists patents for devices of this type for two-cycle engines. Typically, these devices are integrally built into the engine and there exists many attempts to engage the device upon startup by tying it to the starter recoil mechanism or via operator actuated means. However, no patents exist in the art for an aftermarket engine cylinder decompression device that can be used with many types of engines, particularly four-stroke motorcycle engines. Also, it is not always desirable to have the decompression device activated and devices of this type cannot be deactivated.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, the following references were considered related:
U.S. Pat. No. Inventor Issue Date 5,799,635 Aljabari Sep 1, 1998 3,687,124 Kolorz Aug. 29, 1972 5,701,860 Horiuchi et al. Dec. 30, 1997 5,582,143 Stark et al. Dec. 10, 1996 5,379,734 Tsunoda et al. Jan. 10, 1995 5,361,738 Iida Nov. 8, 1994 5,116,287 Hironaka et al. May 26, 1992 5,687,683 Knoblauch Nov. 18, 1997 4,394,851 Greier et al. Jul. 26, 1983 4,184,468 Freyn Jan. 22, 1980 5,630,385 Taomo May 20, 1997 5,377,642 Morrow et al. Jan. 3, 1995 4,993,372 Mott et al. Feb. 19, 1991
Consequently, a need has been felt for providing an aftermarket motorcycle engine decompression device for use during engine startup.